diff options
| author | Kartik K. Agaram <vc@akkartik.com> | 2021-03-15 00:08:08 -0700 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-03-15 00:08:08 -0700 |
| commit | dfd80bf74b32571a4dcf708ea98888894726dba9 (patch) | |
| tree | 3fc4b3e19b9c0f709be219700e1ab4a9fcc35b52 | |
| parent | e0455160142fcbf6ded0a0f4e7d4f9d65b883daf (diff) | |
| download | mu-dfd80bf74b32571a4dcf708ea98888894726dba9.tar.gz | |
first pass translating boot sector
| -rw-r--r-- | boot.subx | 24 |
1 files changed, 5 insertions, 19 deletions
diff --git a/boot.subx b/boot.subx index 5df5c805..4f683c3d 100644 --- a/boot.subx +++ b/boot.subx @@ -19,7 +19,7 @@ # f8 (address 7ca0) <== gdt_descriptor # -- 32-bit mode code # offset 100 (address 7d00): boot code -# 1fe (address 7dfe) boot sector marker (2 bytes) +# 1fe (address 7dfe) boot-sector-marker (2 bytes) # offset 200 (address 7e00): interrupt handler code # -- 32-bit mode data # offset 400 (address 8000): handler data @@ -46,7 +46,7 @@ # Upon reset, the IBM PC: # - loads the first sector (512 bytes) -# from some bootable image (look for the boot sector marker further down this file) +# from some bootable image (look for the boot-sector-marker further down this file) # to the address range [0x7c00, 0x7e00) # - starts executing code at address 0x7c00 @@ -259,6 +259,7 @@ initialize_32bit_mode: fb/enable-interrupts == data + # TODO: SubX doesn't understand db prefix db e3/initialize-floating-point-coprocessor == code # eax <- cr4 @@ -270,27 +271,12 @@ initialize_32bit_mode: == data e9 d0 16 00 00 # jump to 0x9400 [label] -# padding -# 130: -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 - -# 1fe: +== boot-sector-marker 0x7dfe # final 2 bytes of boot sector 55 aa ## sector 2 onwards loaded by load_disk, not automatically on boot +== data # offset 200 (address 0x7e00): # null interrupt handler: |